OBJECTIVEThis research aimed to study the inhibitory effect of xylitol on the growth and acid production of Actinomyces viscosus (A. viscosus).

METHODSWe cultivated A. viscosus in anaerobic conditions with different concentrations (128, 64, 32, 16, 8, and 4 g x L(-1)) of xylitol brain heart infusion liquid medium and determined the minimum inhibitory concentration (MIC). Subsequently, we measured the pH value of the control group, as well as those of 1/2, 1/4, 1/8 MIC, and MIC concentration groups at 1.5, 3, 6, 12, 24, and 48 h. The Delta pH and OD550 at 2, 4, 6, 8, 10, and 12 h were calculated. We discovered that the minimum xylitol concentrations suppressed 50% and 90% A. viscosus biofilm formation (i.e., MBIC50 and MBIC90). SPSS 19.0 was used to analyze the collected data, and conclusions were drawn afterward.

RESULTSXylitol inhibited the growth ofA. viscosus at MIC of 64 g x L(-1). After 12 h, the differences of pH value among groups were all statistically significant (P < 0.05), and Delta pH increased when the MIC concentration decreased. Except for the 1/2 MIC and MIC groups, the differences of OD550 among groups had no statistical significance (P>0.05), and OD550 also increased when the MIC concentration decreased. These results imply that the ability ofA. viscosus to grow and produce acid in 1/2 MIC and MIC conditions will be reduced with the increase in xylitol concentration. The value of MIBC50 was 64 g x L(-1), whereas the value of MIBC90 was 128 g x L(-1). This finding indicates that the xylitol medium can restrict A. viscosus biofilm formation.

CONCLUSIONXylitolcan effectively inhibit the growth, adhesion, and acid production ofA. viscosus, protecting teeth from cariogenic bacteria and preventing caries to a certain extent.

Actinomyces viscosus ; Bacteria ; Dental Caries ; Humans ; In Vitro Techniques ; Xylitol

Objective To explore the relationship between insulin resistance and other metabolic disorders in patients with essential hypertension (EH).Methods Glucose metabolism rate (GMR) was measured by euglycemic insulin clamp technique,and salt sensitivity was tested by increase in blood pressure after salt load and its decreases alter depletion of sodium in 26 healthy subjects and 84 patients with EH.Results GMR lowered significantly in patients with EH than that in healthy subjects,P

Many bioactive peptides from neural and endocrine tissue are amidated at C-terminals,which is essential for their activities.The ?-amide comes from post-translational modification that is catalyzed by ?-AE (?-amidating enzyme) or PAM (pepdilylglycine ?-amidating monooxygenase).The gene encoding ?-AE was amplified with PCR and cloned into the plasmid pET-30a.After the recombinant plasmid pET-A was transformed into E.coli BL21,the ?-AE was expressed and purified by the Ni2+affinity chromatography,which has the ability catalyzing Dns-Tyr-Val-Gly to Dns-Tyr-Val-NH2.It identified that the recombinant protein producing by E.coli BL21 is ?-AE,which will benefit for studies of amidation at the C-terminals of peptides.

Objective To present the technique and short-term results of retroperitoneal laparoscopic renal cryoablation for small renal tumors. Methods Ten selected patients cases with 11 renal tumors were included in present study. There were 3 cases of left renal tumor, 6 cases of right renal tumor and 1 case of bilateral renal tumors. Tumors were located at the upper pole (2), middle (6), or lower pole (3). All tumors were located distant from the collecting system, without evidence of metastatic disease. Mean tumor size was 2. 8 cm (range: 1.5-4.0). All the patients were managed with a double freeze-thaw cycle of retroperitoneal laparoscopic renal cryoablation. The preoperative Hb was (137± 21)g/L, ESR was (27±12)mm/1 h, SCr was (92±41)μmol/L, GFR was (42±10)ml/min.All the patients were taken routine biopsies. Results Cryoablation was technically successful in all 10 patients (11 tumors). The mean time of the operations was (101 ± 31) min, and the mean blood loss was (42±21) ml. None of the cases received blood transfusion post-operation. No operative complication was seen. The postoperative hospital stay was (4±2) d. The postoperative Hb was (129 ±18)g/L,ESR was (31±14)mm/1 h,SCr was (95±39)μmol/L,GFR was (40±11)ml/min. There was no statistic change of Hb, ESR, SCr and ECT-GFR after operations(P＞0. 05). The biopsy results revealed that 8 tumors were renal clear cell carcinomas, and 2 tumors were papillary renal cell carcinomas, and 1 tumor was renal angiomyolipoma. All the patients had a minimum follow-up of 6 months (mean 16, range 6 to 21). Follow-up magnetic resonance imaging at 1, 3, and 6 months identified the punched-out, nonenhancing, spontaneously resorbing, renal cryolesions. Follow-up biopsie of the cryoablated tumor site was negative in the only patient who have undergone the biopsy. No evidence of local or port-site recurrence was found, and no metastatic disease. ConclusionsRetroperitoneal laparoscopic renal cryoablation for small renal tumors could be an accurate and effective intervention with a relatively low incidence of complications. Critical long-term data regarding laparoscopic renal cryoablation are awaited.

ObjectiveTo investigate the protective effect of paraoxonase 1 (PON1) gene against liver oxidative stress injury in mice due to dichlorvos poisoning.Methods Experiment 1: 12 male Balb/c mice were randomly divided into three groups, with 4 mice in each group: control group, green fluorescent protein lentivirus control group (Lv-GFP group), and recombinant PON1 lentivirus group (Lv-PON1 group). 2×107 TU of Lv-GFP or Lv-PON1 was transfected via tail vein, while normal saline was given to those in control group. Blood was collected on 0, 1, 3, 5, 7, 9 days via fundus venous plexus for the assay of serum PON1 activity. PON1 mRNA and protein expression levels were respectively determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western Blot on the 3rd post-lentivirus transfection day. Experiment 2: according to the random number table method, another 96 male Balb/c mice were divided into four groups of 24 mice in each control group, dichlorvos group, Lv-GFP intervention group, and Lv-PON1 intervention group. Lv-GFP or Lv-PON1 was transfected via tail vein followed by intraperitoneal injection of dichlorvos 9 mg/kg, while those in control group were given normal saline. Six mice in each group were sacrificed respectively at 6, 12, 24, 48 hours, and liver tissue was collected. PON1 mRNA and nuclear factor E2-related factor 2 (Nrf2) mRNA expression levels were determined by RT-PCR, and PON1 protein level was determined by Western Blot. The content of malondialdehyde (MDA) and glutathione (GSH) in the liver tissue were determined by chemical colorimetry. The activity of superoxide dismutase (SOD) and catalase (CAT) were measured by double antibody sandwich enzyme linked immunosorbent assay (ELISA).Results Experiment 1: after Lv-PON1 was transfected to normal mice, PON1 activity in serum gradually increased and maintained a high level on 3rd day, while that of the control group and Lv-GFP group showed a normal low level. On the 3rd post-lentivirus transfection day, PON1 mRNA and PON1 protein expressions in liver were significantly higher than those of control group and Lv-GFP group. Experiment 2: compared with control group, the mice in dichlorvos group showed significant decreases in PON1 mRNA, PON1 protein, Nrf2 mRNA as well as GSH, SOD, CAT levels at 6 hours [PON1 mRNA (gray value):0.237±0.075 vs. 0.674±0.011, PON1 protein (gray value): 0.602±0.086 vs. 0.998±0.124, Nrf2 mRNA (gray value): 0.089±0.012 vs. 0.126±0.010, GSH (mg/g): 3.84±0.33 vs. 5.52±0.40, SOD (μg/g): 0.383±0.040 vs. 0.564±0.052, CAT (ng/g): 7.32±1.28 vs. 12.46±1.54, allP< 0.05], and remarkable increase in MDA content (nmol/g: 7.78±0.41 vs. 2.34±0.25,P< 0.05). With the extension of time, PON1 mRNA, PON1 protein, Nrf2 mRNA and GSH, SOD, CAT levels gradually increased, MDA content gradually decreased, Nrf2 mRNA expression level had risen to the level of control group at 24 hours (0.133±0.019 vs. 0.126±0.009,P> 0.05), and it was higher than that of the control group at 48 hours (0.206±0.028 vs. 0.124±0.010,P< 0.05). Compared with that of the dichlorvos group, Lv-PON1 intervention group showed a significant increase in PON1 mRNA, PON1 protein, Nrf2 mRNA and GSH, SOD, CAT levels [PON1 mRNA (gray value): 0.726±0.021 vs. 0.237±0.075, PON1 protein (gray value): 0.739±0.050 vs. 0.602±0.086, Nrf2 mRNA (gray value): 0.158±0.007 vs. 0.089±0.012, GSH (mg/g): 4.30±0.22 vs. 3.84±0.33, SOD (μg/g): 0.454±0.062 vs. 0.383±0.040, CAT (ng/g): 8.98±1.02 vs. 7.32±1.28, allP< 0.05], and a decrease in MDA content (nmol/g: 6.56±0.44 vs. 7.78±0.41,P< 0.05).Conclusion Regulation of PON1 gene can reduce MDA content, enhance SOD and CAT activities, increase GSH content, and it may also up-regulate Nrf2 mRNA expression to play a protective effect against oxidative stress of liver injury induced by dichlorvos poisoning.

White-rot fungi is a kind of basidiomycetes making wood rotten. For their particular metabolism and extracellular degrading ability, they can degrade a lot of organic pollutants, and then become the hot point of international academic research. This paper reviews the recent research progress in many aspects,such as the sort and degradation mechanism of white rot fungus, advances in applied research for white rot fungi on industry and environmental pollution disposal and so on. In addition, some suggestions on the prospective application in the composting of municipal solid waste are presented in the end.

OBJECTIVEThe purpose of this study is to investigate the osteogenic potential and possibility of combination application of mimetic osteoinductive periosteum with tissue-engineered bone.

METHODSThe three-dimensional construction of tissue-engineered bone was made by implantation of adipose derived stromal cells (ADSCs) into rhBMP-2 mediated bio-derived carrier, and mimetic periosteum was constructed by loading ADSCs into Cs-Col-beta3-TCP with rhBMP-2. 10 mm defects of right radiuses were established in adult New Zealand rabbits, group A was transplanted by tissue-engineered bone with mimetic periosteum, group B was implanted by tissue-engineered bone, and group C was implanted by mimetic periosteum, group D was transplanted by bio-derived compound bone as blank scaffold. X-ray, histology, immunohistochemistry stain, dural energy X-ray absorptiometry (DEXA) and transmission electron microscopy (TEM) examinations were performed at different periods.

RESULTSGroup A played a predominant role in process of new tissue regeneration and mature bone reconstitution, defect completely healed at 12 weeks. Group B showed primary repair, group C also existed in modeling stage. While, group D displayed retard regeneration with poor osteogenic capacity. DEXA result showed that group A had statistical significance over control group according to data of BMC and BMD ( P < 0.05).

CONCLUSIONSEnhanced osteogenic potential can be obtained by using tissue-engineered bone with mimetic osteoinductive periosteum. Defect can be healed with concord pattern of osteoinductive and osteopromotive and osteoconductive effects.

Animals ; Biocompatible Materials ; Bone Regeneration ; Bone Substitutes ; Male ; Periosteum ; Rabbits ; Radius ; pathology ; surgery ; Tissue Engineering ; methods

Animal model is an animal material with human mimic performance established in biomedical scientific research. It can be used as experimental basis for studies of experimental hypothesis and clinical hypothesis. It can shorten the research time and observe the whole process of disease occurrence, development or prevention and treatment. Human biomedical research is largely limited by the biological complexity. In order to overcome this limitation, based on the immunosuppressive characteristics of a severely immunodeficient ( SCID) or recombinant activated gene ( Ragnul ) in mice, humanized mouse models of human diseases can be established and have been widely used to study the underlying principles of human immunobiology and complex pathological mechanisms of human diseases. This approach has become one of the important ways to promote the development of medical sciences, with practicality and foresight. In this paper, the application and research progress of humanized mouse models are reviewed.

OBJECTIVETo compare the differences of expressions of adenylyl cyclase (AC) and phosphodiesterase (PDE) in ejaculated spermatozoa between healthy volunteers and the patients with asthenospermia.

METHODSEjaculated spermatozoa were collected from healthy volunteers and the patients with asthenospermia. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect mRNA expression of AC and PDE subtypes in human spermatozoa. The concentrations of cAMP and cGMP in the samples were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTSCompared with healthy volunteers, expression of sAC mRNA and concentration of cAMP were significantly decreased in the patients with asthenospermia (P < 0.01) , while the expression of PDE4C mRNA was significantly increased at the same time (P <0.01). There were no marked differences in the expression of ACIII mRNA and concentration of cGMP between the two groups.

CONCLUSIONThe sAC down-regulation and PDE4C up-regulation are possible reasons for asthenospermia.

Adenylyl Cyclases ; biosynthesis ; Asthenozoospermia ; metabolism ; Cyclic AMP ; metabolism ; Humans ; Male ; Phosphoric Diester Hydrolases ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction ; Spermatozoa ; metabolism

OBJECTIVETo investigate whether calcineurin (CaN) contribute to tumor necrosis factor alpha (TNF-alpha)-induced cardiomyocyte hypertrophy.

METHODSThe protein content was assayed with lowry's method. The cardiomyocytes volumes were measured by computer photograph analysis system. The protein synthesis was assayed with [3H]-leucine incorporation method. [Ca2+]i transient was measured by Till image system by cell-loading Fura-2/AM. The expression of CaN was determined by Western blot.

RESULTS(1) (CsA (0.2 micromol/L), a selective CaN inhibitor, significantly suppressed the increase of protein content, [3H]-leucine incorporation and cell size induced by TNF-alpha. (2) CsA (0.2 micromol/L) significantly suppressed the elevation of the amplitude of the spontaneous Ca2+ transients induced by TNF-alpha in cultured ventricular myocytes from the neonatal rat. (3) TNF-alpha significantly increased the expression of CaN.

CONCLUSIONCa(2+) -CaN signaling pathway are involved in cardiomyocyte hypertrophy induced by TNF-alpha in rats.

Animals ; Calcineurin ; metabolism ; Calcium Signaling ; Cardiomyopathy, Dilated ; metabolism ; pathology ; Cells, Cultured ; Female ; Male ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; pharmacology